青藏高原牦牛感染BVDV和BEV的分子流行病学调查

为了解青藏高原地区牦牛牛病毒性腹泻病毒(BVDV)和牛肠道病毒(BEV)的感染情况,应用RT-PCR对青藏高原地区(西藏、青海、四川和云南)共计222份出现腹泻症状的牦牛粪便样品开展了分子流行病学调查。从222份样品中,检出44份BVDV阳性,BVDV阳性检出率为20%(95%CI:15.5%~25.6%);检出65份BEV阳性,BEV阳性检出率为29.4%(95%CI:24.1%~35.0%);BVDV/BEV混合感染阳性率为4.8%(95%CI:2.5%~8.0%)。结果表明,所有被检地区牦牛均存在BVDV和BEV感染,且部分地区感染较为严重,有混合感染的情况。研究结果旨在为青藏地区牦牛腹泻的综合防控措施提供基本数据,丰富BVDV和BEV的分子流行病学调查资料。     

青海省海北州藏羊群中牛病毒性腹泻病毒和羊边界病毒的流行病学调查

为掌握青海省海北州藏羊群中牛病毒性腹泻病毒和羊边界病毒的感染情况,本研究采用RT-PCR方法分别对青海省海北州的161份健康藏羊血清样品和34份腹泻藏羊组织样品进行了BVDV和BDV的抗原核酸检测。结果显示：195份样品中BVDV和BDV总阳性率分别为29.74 %和14.36 %;161份健康藏羊血清样品中BVDV和BDV平均阳性率分别为26.71 %和11.80 %,BVDV/BDV混合感染率为4.35 %;34份腹泻藏羊组织样品中BVDV和BDV平均阳性率分别为44.12 %和26.47 %,BVDV/BDV混合感染率为17.65 %。本研究表明青海省海北州健康藏羊群和腹泻藏羊群中均存在BVDV、BDV的单独感染以及混合感染,且感染情况在个别养殖场(户)较为严重,本研究为青海藏羊的综合防控措施提供了指导依据,丰富了我国羊群中BVDV和BDV的流行病学资料。     

青海省部分地区3种牛病毒性腹泻病原的感染情况调查

为了解青海省部分牛群中牛病毒性腹泻病毒（bovine viral diarrhea virus,BVDV）、牛轮状病毒（bovine rotavirus,BRV）和牛冠状病毒（bovine coronavirus,BCV）3种牛病毒性腹泻病原的感染现状,本研究采用RT-PCR方法首次对2012～2013年青海省部分地区的32份具有腹泻症状的临床病料及152份健康牛粪便样品进行了BVDV、BRV、BCV的核酸检测与分析。结果显示,32份腹泻牛病料样品中BVDV、BRV、BCV的阳性率分别为65.63%（21/32）、18.75%（6/32）、34.38%（11/32）,且存在2种或3种病原的混合感染;152份健康牛粪便样品中BVDV、BRV、BCV的阳性率分别为3.95%（6/152）、1.97%（3/152）、0（0/152）。该结果表明青海省部分牛群中普遍存在BVDV、BRV、BCV的感染,且混合感染现象严重,需进一步加强青海省地区牛病毒性腹泻病原的综合防控。     

Seroprevalence of bovine tuberculosis infection in yaks (Bos grunniens) on the Qinghai-Tibetan Plateau of China

Bovine tuberculosis (BTB), a chronic disease caused by Mycobacterium bovis, has been widely reported in bovines in developing countries, but there is little information on this infection in domestic yaks. Seroprevalence of antibodies to M. bovis in yaks from six and three regions of Tibet and Qinghai plateau, China, respectively, was investigated in 2011 by enzyme-linked immunosorbent assay kits. A total of 1,244 (Tibet 938, Qinghai 306) blood samples was collected and the results showed that 24 (2.6 %) of Tibetan samples and 3 (1 %) of Qinghai's samples were positive for BTB. The findings of the present study indicated that M. bovis infection is prevalent in Chinese yaks in Qinghai and Tibet. These observations should raise a serious public health concern considering the extent to which the herdsmen of the study areas are in contact with their animals and the levels at which they use untreated livestock products. This is the first study showing the infection of M. bovis in domestic yaks.     

川西北牦牛3种病毒性腹泻病血清学调查

The objective of this study was to investigate the epidemic of three viral diarrhea diseases of yaks in northwest Sichuan province and provide certain scientific basis for controlling this kind of disease. 1070 yak serum samples from 8 counties of Aba state in northwest Sichuan province were detected by enzyme-linked immunosorbent assay (ELISA) to investigate prevalence of BVDV, BCV and BRV. The results showed that the average positive rates of BVDV, BCV and BRV antibody were 44.3%, 84.1% and 94.4%, respectively. The BVDV, BCV and BRV of yaks were widespread in northwest Sichuan province, further comprehensive prevention and control measures of viral diarrhea diseases should be strengthened in this region.     

Identification of bovine viral diarrhea virus type 1 in yaks (Bos poephagus grunniens) in the Himalayan region

Since cattle are widely infected by bovine viral diarrhea virus (BVDV) in India, we searched for pestivirus infection in yaks. Of 71 pure and crossbred yaks from Himalayan region, pestivirus antigen was detected by Ag-ELISA in three animals. Pestivirus in leukocyte and cell culture isolated virus samples originating from positive yaks was also confirmed by RT-PCR using panpestivirus specific primers selected from 5'-untranslated region (5' UTR). The 5' UTR, N(pro) and E2 regions were sequenced and used for genetic typing. Phylogenetic analysis revealed that pestiviruses detected in three Himalayan yaks were similar genetically, belonging to BVDV-1. Antigenic characterisation of yak pestivirus also confirmed the typing as BVDV-1. This is the first report on the identification of BVDV type 1 in yaks.     

重庆肉牛腹泻相关病毒的检测及遗传进化分析

为了解重庆市肉牛病毒性腹泻的病原流行情况,本研究对重庆市8个肉牛养殖场的81份腹泻粪便样本中牛病毒性腹泻-黏膜病病毒（bovine viral diarrhea virus,BVDV）、牛冠状病毒（bovine coronavirus,BCV）、牛轮状病毒（bovine rotavirus,BRV）和牛星状病毒（bovine astrovirus,BAstV）4种致腹泻病毒进行了RT-PCR检测,对PCR产物进行测序,用Mega 6.0软件进行系统发育分析。结果显示,BRV、BAstV和BVDV检出率分别为66.7%、8.6%和7.4%,BCV未检出。遗传进化分析结果表明,测序的5个BRV单独聚为一小支,与GenBank中其他VP6序列有明显的遗传距离;BVDV与中国株和丹麦株聚为一支,遗传关系最近;5个BAstV单独聚为一支,与中国香港株遗传关系最近,但仍有明显的遗传距离。本试验结果表明,重庆地区肉牛腹泻主要发生在6月龄以下犊牛,BRV是该地区肉牛腹泻的重要原因,BRV、BAstV和BVDV 3种病毒的遗传多样性值得进一步关注。     

Detection and Genetic Evolution of Diarrhea-related Viruses in Chongqing Beef Cattle

In order to investigate the pathogen prevalence of bovine viral diarrhea in Chongqing, this study carried out an investigation of bovine viral diarrhea virus (BVDV), bovine coronavirus (BCV), bovine rotavirus (BRV) and bovine astrovirus (BAstV) on a total of 81 diarrhea samples of beef cattle which were collected from Chongqing by RT-PCR. After the PCR products were sequenced, phylogenetic analysis was performed with Mega 6.0 software. From 81 samples, the positive rate of BRV,BAstV and BVDV were 66.7%,8.6% and 7.4%, respectively,BCV was not detected.Phylogenetic analysis showed that 5 strains of BRV sequences were clustered into a small branch, which had significant genetic distance with other VP6 sequences in GenBank; 5 strains of BVDV, Chinese and Denmark strains were clustered into one branch,genetic relationship were close; 5 strains of BAstV clustered into a branch with Hongkong strain, but there was still an obvious genetic distance. The result showed that calves under the age of half year were the main group of beef cattle with diarrhea in Chongqing. BRV was an important cause of diarrhea in Chongqing, the genetic diversity of BRV,BAstV and BVDV could be reference to further concern.     

牛病毒性腹泻病毒、大肠杆菌和奇异变形杆菌混合感染致犊牛腹泻的研究

为确定甘肃省临夏州某奶牛场犊牛腹泻的病因,并提供合适的治疗方案和防控措施,试验采集该牛场13头腹泻犊牛的粪便和血清,通过胶体金技术、ELISA方法、细菌分离鉴定、Kirby-Bauer法分别进行病毒病原学检测、病毒血清学抗体检测、病原菌鉴定和药物敏感性试验。病毒学检测结果显示,13份粪样中未检测出牛轮状病毒（BRV）、牛冠状病毒（BCV）的抗原,牛病毒性腹泻病毒（BVDV）抗原阳性率为23.08%（3/13）;未检出BRV和BCV的抗体,BVDV血清学抗体阳性率为38.46%（5/13）。病原菌检测结果显示,13份粪便样品中,分离出13株大肠杆菌和7株奇异变形杆菌。药敏试验表明,分离的大肠杆菌和奇异变形杆菌对20种常规药物均产生了不同程度的耐药,且无对两种细菌均有效的药物。此次犊牛腹泻是由BVDV、大肠杆菌、奇异变形杆菌混合感染引起的,且大肠杆菌和奇异变形杆菌的耐药现象严重,本试验结果为该牛场进一步治疗此次的犊牛腹泻病提供了合理有效的依据。     

北京地区规模化奶牛场三种病毒性腹泻病的血清学调查

为了解近年北京地区奶牛腹泻性疾病的流行情况,采用酶联免疫吸附试验(ELISA)对北京地区密云、怀柔和昌平3个区县的未免疫接种牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)、牛冠状病毒(Bovine coronavirus,BCV)和牛轮状病毒(Bovine rotavirus,BRV)疫苗的31个规模化奶牛场的1 650份血清样品进行了BVDV、BCV、BRV感染抗体检测。结果显示,BVDV抗体平均阳性率为48.2%,BCV抗体平均阳性率为57.2%,BRV抗体平均阳性率为52.2%,BVDV、BCV及BRV感染在密云、怀柔和昌平3个区县的牛群中普遍存在,需进一步加强奶牛腹泻性疾病的综合防控。     

甘肃、青海和宁夏地区牛病毒性腹泻病毒Erns基因的变异分析

分析2013—2019年中国西北部分省区不同基因亚型牛病毒性腹泻病毒（BVDV）抗原基因E^rns的分子特征,了解其遗传演化规律。从甘肃、青海、宁夏规模化牛场送检的疑似牛病毒性腹泻发病牛150份EDTA抗凝血提取总RNA,利用RT-PCR扩增病毒基因组E^rns-E1区,克隆测序后比对,构建系统进化树进行遗传演化关系分析。利用牛肾细胞MDBK对检出的不同基因亚型BVDV进行分离,并鉴定其生物型。RT-PCR扩增结果表明,BVDV总体阳性率为37.33%,其中甘肃省、青海省、宁夏回族自治区BVDV阳性率分别为37.68%、35.71%、40.00%。获得56份E^rns-E1 DNA,克隆测序获得33条不同的E^rns序列,长度均为681 bp,分析表明流行株分属10个BVDV基因亚型：BVDV-1a （2株）、BVDV-1b （5株）、BVDV-1c （1株）、BVDV-1d （3株）、BVDV-1m （11株）、BVDV-1o （1株）、BVDV-1p （4株）、BVDV-1q （4株）、BVDV-1v （1株）、BVDV-2a （1株）。分离获得BVDV-1a亚型、BVDV-1b亚型、BVDV-1v亚型、BVDV-2a亚型分离株各1株,BVDV-1 d亚型分离株2株,均为非致细胞病变型。各亚型株间E^rns基因核苷酸相似性以BVDV-1a～1d经典亚型株（79.8%～85.9%）或1m～1q及1v新亚型株（81.0%～87.3%）较高,以BVDV-1 m和BVDV-1p流行株亚型间相似性最高（87.3%）。各亚型株E^rns基因编码蛋白的RNA酶活性位点以及双链RNA作用基序（₁₃₉KKGK₁₄₂）保守,但E^rns第26位糖基化位点（26 NRSL）在1m～1q、1v亚型株移位（24 NVSR）。首次以E^rns核苷酸序列构建系统进化树,结果显示1m～1q及1v等亚型BVDV株在进化上关系较为密切。本研究首次选用E^rns靶标基因对甘肃、青海、宁夏部分省区牛源BVDV株进行同源性及系统进化分析,发现10个基因亚型流行株,以1m亚型株最为普遍,1m～1q及1v等亚型株亲缘关系密切。     

一起奶牛腹泻病的病原学诊断

辽宁省某奶牛养殖场10～30日龄犊牛发生腹泻,为查明病因,我们对送检的18份犊牛腹泻样本分别进行牛轮状病毒(BRV)、牛冠状病毒(BCoV)、牛病毒性腹泻病毒(BVDV)、产肠毒素大肠杆菌(ETEC)、沙门氏菌(Salmonella)和安氏隐孢子虫(C. andersoni)的PCR检测。结果显示:18份犊牛腹泻样本中,BRV、BCoV、BVDV的检出率分别为83.3%(15/18)、88.9%(16/18)、61.1%(11/18),这3种病原的混合感染率较高,其他病原均未检出,说明该奶牛场的犊牛腹泻主要由BRV、BCoV、BVDV混合感染引起。     

Viral contamination of bovine fetal lung cultures and bovine fetal serum

Commercial bovine fetal serum (BFS) and bovine fetal lung (BFL) cells were tested for viruses. The only virus detected in any samples was noncytopathogenic bovine viral diarrhea virus (BVDV). Of 37 BFL cultures initiated, 34 were negative for BVDV, 1 was positive, and 2 were suspicious in that the source of BVDV contamination was not certain. Of 9 lots of irradiated sera tested, 1 (10%) was positive for BVDV; of 21 lots of nonirradiated sera tested, 13 (62%) were positive for BVDV. As judged by intensity of fluorescence in infected cultures, some cell strains were much more susceptible to BVDV than other strains. Heat inactivation of serum at 56 C for 30 minutes was found to be an unreliable method of eliminating BVDV from sera.     

Evaluation of transmission of bovine viral diarrhea virus (BVDV) between persistently infected and naive cattle by the horn fly <Emphasis Type="Italic">(Haematobia irritans)</Emphasis>

Identifying reservoirs and transmission routes for bovine viral diarrhea virus (BVDV) are important in developing biosecurity programs. The aim of this study was to evaluate BVDV transmission by the hematophagous horn fly (Haematobia irritans). Flies collected from four persistently infected cattle were placed in fly cages attached to principal (n?=?4) and control (n?=?4) BVDV-naïve calves housed individually in isolation rooms. Flies were able to feed on principal calves, but a barrier prevented fly feeding from control calves. Flies were tested for BVDV by RT-PCR and virus isolation at time of collection from PI cattle and after 48 h of exposure on BVDV-naïve calves. Blood samples were collected from calves and tested for BVDV infection. Virus was isolated from fly homogenates at collection from PI animals and at removal from control and principal calves. All calves remained negative for BVDV by virus isolation and serology throughout the study. Bovine viral diarrhea virus may be detected in horn flies collected from PI cattle, but horn flies do not appear to be an important vector for BVDV transmission.     

猪繁殖与呼吸综合征病毒和牛病毒性腹泻病毒双重RT-PCR检测方法的建立

根据牛病毒性腹泻病毒(BVDV)5'端非编码区基因序列,设计合成了1对特异性引物,参考本实验室针对猪繁殖与呼吸综合征病毒(PRRSV)N蛋白设计的引物,经过PCR反应条件的优化,建立了BVDV和PRRSV双重RT-PCR的检测方法。对于PRRSV和BVDV的cDNA最低检测量分别为3.8×10-4 ng和7×10-4 ng,对于猪瘟病毒(CFSV)、脑心肌炎病毒(EMCV)和猪圆环病毒2型(PCV-2)的PCR扩增结果均为阴性;用该方法对江苏省不同地区采集的75份仔猪的肺脏、脾脏和淋巴结等病料进行了检测,结果PRRSV有55份阳性,BVDV有14份阳性,PRRSV和BVDV混合感染的有12份,与PRRSV和BVDV单一RT-PCR的检测结果符合率分别为89.3%和92%。证明建立的双重RT-PCR检测方法可用于临床样品中BVDV和PRRSV的检测。     

Seroprevalence and factors associated with bovine viral diarrhea virus (BVDV) infection in dairy cattle in three milksheds in Ethiopia

This work was conducted to estimate the seroprevalence, to identify potential factors that influence seroprevalence of bovine viral diarrhea virus (BVDV), and to investigate the association between BVDV serostatus and occurrence of reproductive disorders in dairy cattle in three milksheds in Ethiopia. A total of 1379 serum samples were obtained from cattle randomly selected from 149 herds from three milksheds representing central, southern, and western Ethiopia. Sera samples were examined for bovine viral diarrhea virus (BVDV) antibodies using commercial competitive enzyme-linked immunosorbent assay (ELISA) kit. Logistic regression analysis was employed to investigate associations between risk factors and the risk of BVDV seroprevalence, and BVDV serostatus and reproductive disorders. Seroreaction to BVDV antigens was detected in 32.6% of the 1379 cattle and 69.8% of the 149 herds sampled. Factors associated with BVDV seroplevalence were age, breed, and herd size (P?<?0.05). Adult cattle ≥?18 months old had 2.1 (95% CI 1.5, 3.1) times the odds of BVDV seroreaction than younger cattle. Holstein-Friesian (HF) local crosses (OR?=?2.1, 95% CI 1.3, 3.4) and HFs (OR?=?1.3, 95% CI 0.9, 1.9) were more likely to be seropositive than Jersey and the odds of seropositivity in cattle in large herds with 11 or more animals were higher (OR?=?1.8, 95% CI 1.3, 2.5) than the odds of BVDV seropositivity in smaller herds. Seroprevalence was not associated with geographical region (P?>?0.05). Risk of reproductive disorders was not affected by BVDV serostatus, except for repeat breeding (P?>?0.05). The present study demonstrated that BVDV has wide distribution in the country being detected in all the 15 conurbations and 69.8% of herds involved in the study.     

Seroprevalence of Chlamydophila abortus infection in yaks (Bos grunniens) in Qinghai,China

Chlamydophila abortus is an important amphixenosis which in a wide range of animals, associated with reproductive disorders in yaks. In order to assess the prevalence of this infection in yaks in Qinghai, China, a cross-sectional study was carried out, and a total of 674 serum samples were collected from June to October 2012 in six counties, and antibodies to C. abortus were examined by indirect hemagglutination (IHA) test. The overall seroprevalence of C. abortus in yaks was 17.66 % (119/674), and the seroprevalence of antibodies to C. abortus in yaks ranged from 11.82 to 28.43 % among the six different areas, and the difference was statistically significant (P?<?0.05). The seropositivity of C. abortus infection in different age groups varied from 16.33 to 18.49 %, and prevalence in yaks of ≥3 year (18.49 %) was slightly higher than that in yaks of <3 year, but the differences among the age groups were not statistically significant (P?>?0.05). The seroprevalence of C. abortus infection in male yak (16.8 %) was slightly lower than that in females (17.85 %), and the difference was not statistically significant (P?>?0.05). So far, this is the first systematic and comprehensive investigation of C. abortus infectionin in yaks in this area.     

Prevalence of bovine viral diarrhea virus infection in bulls in artificial insemination centers in Poland

This study was directed at the evaluation of the prevalence of bovine viral diarrhea virus (BVDV) infection in bulls in artificial insemination centers. Both serological and virological examinations were performed. Blood samples were tested in micro-seroneutralization test for BVDV antibodies. Virus isolation was performed in cell culture and BVDV antigen was detected in an indirect immunofluorescence assay with monoclonal antibodies. One hundred and seventy-five serum samples and 219 whole blood samples for virus isolation were tested. Neutralizing antibodies were found in 86% of the bulls. Persistent infection (PI) was detected in 0.9% of the analyzed blood samples.     

规模化奶牛场犊牛腹泻的病原检测与分析报告

为了调查某规模化奶牛场犊牛腹泻的发病原因,试验采用血清抗体检测、细菌分离培养、寄生虫卵镜检和病毒核酸检测方法对腹泻犊牛的血样和粪便进行了检查。结果表明,该奶牛场牛病毒性腹泻/黏膜病病毒抗体阳性率为65.00%,牛轮状病毒抗体阳性率25.00%,牛冠状病毒抗体阳性率15.00%;分离到1 株结肠弯曲杆菌和1 株空肠弯曲杆菌;所检腹泻犊牛粪便和血液样品中,4 份粪便样品和1 份血液样品检出牛冠状病毒,2 份粪便样品检出轮状病毒,1 份粪便样品和1 份血液样品检出牛病毒性腹泻/黏膜病病毒,同一份粪便样品中同时检出牛病毒性腹泻/黏膜病病毒和牛冠状病毒;通过镜检,球虫卵囊检出率77.78%,在1 份粪样中发现蛔虫卵,2 份粪样中发现其他线虫卵。该牛场流行性腹泻的原因可能为夏季高温潮湿引起犊牛免疫力下降导致的多病原体感染。     

新疆部分规模奶牛场牛病毒性腹泻病的流行情况调查与防控措施

为了解新疆地区部分规模奶牛场牛病毒性腹泻病（BVD）的流行情况,优化防控措施,以达到建设防控净化场的目的,自2020年11月到2021年7月累计采集新疆5 个地区16 个奶牛场共计26 997 份血清、3 843 份犊牛耳组织进行全群普检。通过使用IDEXX公司牛病毒性腹泻病毒（BVDV）抗原检测试剂盒检测及RT-PCR复检结合测序等方法,淘汰阳性牛,同源性分析流行毒株情况。BVDV血清抗原检测结果为：沙湾某奶牛场BVD阳性率为1.63%（38/2 326）;乌鲁木齐某奶牛场BVD阳性率为0.35%（4/1 132）;其余奶牛场均为阴性。犊牛耳组织抗原检测结果为：乌鲁木齐某牛场BVDV阳性率为1.17%（4/342）;其余奶牛场均为阴性。研究结果揭示,奶牛场通过淘汰BVDV阳性牛,调整免疫程序、制定消毒程序等方法,可有效净化BVD。